In semiconductor device fabrication, back-end-of-line (BEOL) wafer processing generally involves creating various interconnecting metal layers that may be interconnected by vias. Pads are connected to the interconnects. The pads provide external electrical connection to internal components of an integrated circuit (IC) to other ICs or electronic devices. The pads may be used for wire bonding or bumping in the case of wafer level packaging.
In conventional processing, the pads are subject to high temperature processes, such as alloying process. Such high temperature processes cause hillocks to form on the surfaces of the bonding pads. The hillock increases surface roughness, which negatively impact bonding reliability and package integrity of the device.
The present disclosure relates to providing more reliable bonding pad with improved surface smoothness over conventional bonding pads.